I also have a gaming channel and only been doing YouTUbe for 3 months so I'll do my best to help ^^
The only things you can grow is by playing any latest games that are released (the ones that is popular at least)
Well, that's actually true,, I don't consider myself a true gamer but the games you play are for a certain niche that will take years to grow I guess
Remove XX from name: You want people to find you easily on YT, there's no way people will search for those XX XX. I like my name cause if you google it: Gamevestment I'M the FIRST result on Google and Youtube
Thumbnails are fine: I guess they could be better if you really try it, try to keep them more simple (look at mine for an example)
Intro: Your intro feels kind of old (every gaming channel has that type of intro), maybe you can find something different or more original, I actually found mine on Panzoid
Quality is good: Mic sound is ok and video looks really nice so you don't need to worry about that. Maybe only worry about content and see what your subscribers want to see, funny stuff or maybe tutorials etc.
That's all I could think of, I don't think Is YouTube's fault I just think your content is hard to find and since there's a lot of variety well, is hard to subscribe. When you have a big audience and they will watch whatever you post then yeah,, you can upload all type of different games I guess.
This is what I gathered with my experience, hopefully it will be helpful and don't give up,,,, just keep grinding that's how you grow!
